How can I share global ClsModule between my NodeJS app and a package I've installed

[kasir-barati]

Hi,

I am initiating the ClsModule like this in my NodeJS app:

import { ClsModule } from 'nestjs-cls'
import { MyCustomModule } from 'my-custom-lib'

@Module({
  imports: [
    ClsModule.forRoot({
      global: true,
      interceptor: { mount: true },
    }),
    MyCustomModule.forRoot({
      isGlobal: true,
    }),
  ]
})
export class AppModule {}

And now I have another package (published as npm lib) which is injecting the ClsService, but I get the following error:

/usr/src/app/node_modules/my-custom-lib/dist/request-utils/correlation-id.service.js:20
        return this.clsService.get("some-key");
                                       ^
TypeError: Cannot read properties of undefined (reading 'get')
    at CorrelationIdService.correlationId (/usr/src/app/node_modules/my-custom-lib/dist/request-utils/correlation-id.service.js:20:40)
    at Format.transform (/usr/src/app/node_modules/my-custom-lib/dist/winston/winston.factory.js:21:51)
    at Format.transform (/usr/src/app/node_modules/logform/combine.js:20:24)
    at DerivedLogger._transform (/usr/src/app/node_modules/winston/lib/winston/logger.js:314:29)
    at DerivedLogger.Transform._read (/usr/src/app/node_modules/readable-stream/lib/_stream_transform.js:166:10)
    at DerivedLogger.Transform._write (/usr/src/app/node_modules/readable-stream/lib/_stream_transform.js:155:83)
    at doWrite (/usr/src/app/node_modules/readable-stream/lib/_stream_writable.js:390:139)
    at writeOrBuffer (/usr/src/app/node_modules/readable-stream/lib/_stream_writable.js:381:5)
    at DerivedLogger.Writable.write (/usr/src/app/node_modules/readable-stream/lib/_stream_writable.js:302:11)
    at DerivedLogger.log (/usr/src/app/node_modules/winston/lib/winston/logger.js:253:14)

So I know if I define another ClsModule in my lib then my package will not share the same ClsModule which results in not getting the same value in my node app and the lib. So what can I do about this?

I guess I can send the ClsService to the lib somehow but I do not have a clear idea how to do it. I tried this but it fails:

import { ClsModule } from 'nestjs-cls'
import { MyCustomModule } from 'my-custom-lib'

@Module({
  imports: [
    ClsModule.forRoot({
      global: true,
      interceptor: { mount: true },
    }),
    MyCustomModule.forRoot({
      isGlobal: true,
      providers: [ClsService], // But this does not work
    }),
  ]
})
export class AppModule {}

The error message is this:

Error: Cannot create ClsService because no AsyncLocalStorage instance was provided.
Please make sure that ClsService is only provided by the ClsModule and not constructed manually or added to the providers array.
    at new ClsService (/usr/src/app/node_modules/nestjs-cls/dist/src/lib/cls.service.js:35:19)
    at Injector.instantiateClass (/usr/src/app/node_modules/@nestjs/core/injector/injector.js:365:19)
    at callback (/usr/src/app/node_modules/@nestjs/core/injector/injector.js:65:45)
    at async Injector.resolveConstructorParams (/usr/src/app/node_modules/@nestjs/core/injector/injector.js:144:24)
    at async Injector.loadInstance (/usr/src/app/node_modules/@nestjs/core/injector/injector.js:70:13)
    at async Injector.loadProvider (/usr/src/app/node_modules/@nestjs/core/injector/injector.js:97:9)
    at async /usr/src/app/node_modules/@nestjs/core/injector/instance-loader.js:56:13
    at async Promise.all (index 7)
    at async InstanceLoader.createInstancesOfProviders (/usr/src/app/node_modules/@nestjs/core/injector/instance-loader.js:55:9)
    at async /usr/src/app/node_modules/@nestjs/core/injector/instance-loader.js:40:13

[kasir-barati]

I guess I've found the answer, but I would like to confirm that the ClsService will be able to share the same storage between my app and custom lib:

If your library code needs to inject ClsService, it should be done by importing the ClsModule statically, without calling forRoot().

Ref.

[kasir-barati]

@Papooch It did not work: kasir-barati/nestjs-backend-common@7d3a462

Any other comment?

[Papooch]

Right, strange. I'll try jt myself later. There might be an issue related to PNPM. Would you try deleting node modules in the application and performing an install with NPM?

[kasir-barati]

Hmm, I will try that too. But I hardly can believe that will be able to solve any issue

[Papooch]

@kasir-barati Ah, so I cloned your project and found the problem. You're missing the flag emitDecoratorMetadata in your shared library's tsconfig.json.

That means a built source of the CorrelationIdInterceptor doesn't contain any metadata that NestJS can read to inject dependencies, so it doesn't inject anything, and therefore stuff is undefined at runtime.

Once I added that flag and rebuilt the library, it works as intended. An alternative to enabling that flah is to explicitly decorate the constructor parameter with @Inject(ClsService).